In a known storage phosphor reader, a cassette containing a storage phosphor is located at a cassette receiving station where the cassette is clamped to the reader. A storage phosphor extraction mechanism extracts the storage phosphor from the cassette and moves the storage phosphor onto a stage. The stage moves the storage phosphor past a laser scanning reading station where the latent radiographic image stored in the phosphor is converted to a radiographic image signal.
An extraction mechanism used in such reader includes a hook bar assembly and a locating pin (See: U.S. Pat. No. 5,330,309, issued Jul. 19, 1994, inventors Brahm et al). The assembly is initially moved so that the locating pin contacts the front end of the storage phosphor. The assembly is then moved laterally of the cassette until the locating pin falls into a reference opening in the front end of the storage phosphor. The extractor assembly is then moved relative to the cassette to engage the hook bar assembly with the storage phosphor to unlatch the storage phosphor and to subsequently remove the storage phosphor from the cassette onto a stage. Rollers mounted on the stage support the storage phosphor during loading and unloading and during reading. These rollers have been known to interfere with the extraction and insertion process. Moreover, vibration of rollers and supported storage phosphor can occur.